Roller bumper for chain saw bar



FIG. 1 is a perspective view of a roller bumper for chain saw bar showing my new design;

FIG. 2 is a right side elevational view as viewed in FIG. 1;

FIG. 3 is a bottom view thereof;

FIG. 4 is a left side elevational view as viewed in FIG. 1;

FIG. 5 is a front view; and,

FIG. 6 is a rear view.

The driving motor shown in broken lines in FIG. 1 denotes the nature and environmental use of the design and is not part of the design. 

The ornamental design for a roller bumper for chain saw bar, as shown. 